The Iraq war veteran could use post-traumatic stress disorder as a defense.

In the two days he was in custody following the shooting death of his wife, Sebena slowly revealed details about their lives together and eventually, according to prosecutors, admitted to shooting her five times in the head.

Surveillance video collected by investigators and obtained by WISN 12 News shows a car believed to be Sebena's driving past a Menomonee Falls gas station near their home in the early morning hours when Sebena originally claimed he was at home.

That car could provide a glimpse to a possible legal defense.

Documents also obtained by WISN 12 News for a search warrant executed at Sebena's home last Wednesday, reveal "Sebena stated he bought the Toyota Prius to help/force him to drive slower as he suffered from the effects of post traumatic stress disorder" from his time in Iraq.

"It's an incredibly hard thing to do," attorney John Carini said.

Attorney John Carini once successfully defended a Vietnam War veteran charged with vehicular homicide.

"We were able to win in that case on a not guilty by reason of mental disease or defect based on PTSD," Carini said.

But Carini, who isn't currently practicing because of health issues, said the defense team would have to medically prove Sebena was incapable of obeying the law.

"But if he was being treated appropriately, then it would be, in my opinion, much more difficult to meet the legal standard," Carini said.

Sebena's mental state, however, could come into play even before a trial.

Carini said he suspects the defense team will question whether Sabena's confession without legal counsel present is admissible.